1. Field of the Invention
The present invention relates to an air feeder used for a substrate processing apparatus for coating a substrate, for example, a semiconductor wafer, a glass substrate for a liquid crystal display device, or the like with a resist and developing the substrate, a substrate processing apparatus including the air feeder, and an air supply method.
2. Description of the Related Art
In the photolithography of a semiconductor wafer (hereinafter referred to as xe2x80x9ca waferxe2x80x9d), a wafer is coated with a resist, and subsequently a pattern is exposed and then developed. A coating and developing system in which processing units each for performing processing individually are integrated is conventionally used for such a series of processings.
In the above coating and developing system, as to resist coating processing, for example, a wafer is spun within a processing container to thereby diffuse a resist on the wafer by centrifugal force, and thus a resist film with a predetermined thickness is formed on the wafer. The thickness of the resist film is very sensitive to temperature and humidity, and hence air set at a predetermined temperature and humidity is supplied into the processing container.
The air is supplied from an attached air feeder. The air feeder introduces an atmosphere inside a clean room, for example, and includes a cooling section for cooling the introduced air, a heating section for heating the air, a humidifying section for humidifying the air, and a blower for supplying the air into the processing container for performing the resist coating processing. The air is once cooled to the vicinity of a dew-point temperature, for example, 5xc2x0 C. by a refrigerator in the cooling section, thereafter heated by heating to attain a predetermined temperature and relative humidity, and finally moisture necessary for the predetermined relative humidity is given by the humidifying section.
In the air feeder configured as above, however, the introduced air is introduced in full to the cooling section, and all of the air is once cooled to the vicinity of a dew-point temperature and dehumidified, and thereafter heated and humidified. Hence, consumed energy in the cooling section, the heating section, and the humidifying section is large. Moreover, the air feeder is increased in size, thus causing a waste of installation space.
An object of the present invention is to provide a new substrate processing apparatus, air feeder, and air supply method capable of energy-saving and space-saving temperature and humidity control.
To attain the above object, a first aspect of the present invention is a substrate processing apparatus comprising a processing container for processing a substrate and an air feeder for controlling temperature and humidity of air introduced from an air inlet and supplying the air to the processing container, in which the air feeder comprises a cooling section for cooling the air introduced from the air inlet, a by-pass for allowing the air introduced from the air inlet to bypass the cooling section, a mixing section for mixing the air cooled by the cooling section and the air bypassed by the by-pass, a heating section for heating the air mixed by the mixing section, and a humidifying section for humidifying the air heated by the heating section.
A second aspect of the present invention is a substrate processing apparatus comprising a processing container for processing a substrate and an air feeder for controlling temperature and humidity of air introduced from an air inlet for introducing part of air exhausted from the processing container and air outside the substrate processing apparatus and supplying the air to the processing container, in which the air feeder comprises a cooling section for cooling the air introduced from the air inlet, a by-pass for allowing the air introduced from the air inlet to bypass the cooling section, a blower for blowing the air introduced from the air inlet into the cooling section and the by-pass, a mixing section for mixing the air cooled by the cooling section and the air bypassed by the by-pass, a heating section for heating the air mixed by the mixing section, and a humidifying section for humidifying the air heated by the heating section.
A third aspect of the present invention is an air feeder for controlling temperature and humidity of air introduced from an air inlet and supplying the air to a processing container for processing a substrate, comprising a cooling section for cooling the air introduced from the air inlet, a by-pass for allowing the air introduced from the air inlet to bypass the cooling section, a mixing section for mixing the air cooled by the cooling section and the air bypassed by the by-pass, a heating section for heating the air mixed by the mixing section, and a humidifying section for humidifying the air heated by the heating section.
A fourth aspect of the present invention is an air supply method for controlling temperature and humidity of air and supplying the air to a processing container for processing a substrate, comprising the steps of dividing the air to be supplied between a first passage and a second passage, cooling the air divided for the first passage, mixing the air divided for the first passage and cooled therein and the air divide for the second passage, heating the mixed air, and humidifying the heated air.
In the present invention, for example, 55% of air introduced from the air inlet of the air feeder is cooled by passing through the cooling section. Meanwhile, the remaining 45% of the air is bypassed without passing through the cooling section and maintained in the state in which it was introduced from an inlet side. In this case, nearly half of the air only is cooled in the cooling section, thus reducing consumed electric power during cooling as compared with the case where all of the introduced air is cooled. After the cooled air and the air from the by-pass are mixed, the mixed air is heated in the heating section, and finally humidified in the humidifying section. In this case, the temperature and relative humidity of the mixed air are higher in comparison with the case all of the introduced air is cooled, whereby consumed electric power during heating and humidification can be also reduced. As a result, energy-saving temperature and humidity control becomes possible. Further, designs and the like of the cooling section, the heating section, and the humidifying section can be one size smaller than in the prior art owing to the energy saving. Consequently, it becomes possible to downsize the feeder.
These objects and still other objects and advantages of the present invention will become apparent upon reading the following specification when taken in conjunction with the accompanying drawings.